Aerosol systems that use a propellant gas to deliver highly viscous products, such as cheese or churro dough (food industry), and caulking materials, are known. Generally, in such applications, the product formulation and propellant gases are physically separated by a barrier, such as a bag. The propellant, which exists outside the bag, pushes on the bag after an aerosol actuator is acted upon to deliver the material contained inside the bag. Since the product being delivered is physically isolated from the aerosol can body and valve cup components, incompatibility or corrosion potential amongst the product and steel-like alloys is not a concern. While this technology (commonly known as bag-in-valve or bag-in-can) has become widely adopted for some products, these non-traditional aerosol components are substantially more expensive and cumbersome to handle in a production line than traditional aerosol dispensers. Thus, due to processing and cost considerations, such non-traditional aerosol systems are not considered to suitable for certain categories of products, such as bathroom cleaners. Another available alternative currently is the usage of aerosol cans made of inert metals and alloys, such as aluminum. Like bag based technologies, however, aluminum components are more expensive than traditional steel-based aerosol dispensers.
Unfortunately, the tin-plated steel cans that are typically used as dispensers for viscous aerosol materials will readily corrode if in contact with materials having the pH of typical toilet cleaning gels, e.g., a pH of about 4 to 6. While it is known that increasing the pH of a water containing formulation can reduce corrosion of steel in contact with the formulation, the effect of the addition of basic materials on the physical properties of a given formulation is unclear. The effects of such formulation changes by adding basic materials to cleaning gel materials to alter the pH, could lead to changes in gel rheology, the sensorial properties, delivery attributes, lastingness, surface adhesion and/or drying properties of the cleaning gels. If basic agents were to be added to a cleaning gel formulation to raise its pH, it should desirably be done in a manner that does not adversely affect other desirable properties of the gel, such as its rheology profile (e.g., gelling point, yield stress), surface adhesion characteristics, wettability, moisture retention, durability/dissolution profile in aqueous environments (e.g., after a number of toilet flushes) and fragrancing capabilities, amongst others.